From: Sean Christopherson <sean.j.christopher...@intel.com> Omit HPET AML if the HPET is disabled, QEMU is not emulating it and the guest may get confused by seeing HPET in the ACPI tables without a "physical" device present.
The change of DSDT when -no-hpet is as follows. @@ -141,47 +141,6 @@ DefinitionBlock ("", "DSDT", 1, "BOCHS " } } - Scope (_SB) - { - Device (HPET) - { - Name (_HID, EisaId ("PNP0103") /* HPET System Timer */) // _HID: Hardware ID - Name (_UID, Zero) // _UID: Unique ID - OperationRegion (HPTM, SystemMemory, 0xFED00000, 0x0400) - Field (HPTM, DWordAcc, Lock, Preserve) - { - VEND, 32, - PRD, 32 - } - - Method (_STA, 0, NotSerialized) // _STA: Status - { - Local0 = VEND /* \_SB_.HPET.VEND */ - Local1 = PRD /* \_SB_.HPET.PRD_ */ - Local0 >>= 0x10 - If (((Local0 == Zero) || (Local0 == 0xFFFF))) - { - Return (Zero) - } - - If (((Local1 == Zero) || (Local1 > 0x05F5E100))) - { - Return (Zero) - } - - Return (0x0F) - } - - Name (_CRS, ResourceTemplate () // _CRS: Current Resource Settings - { - Memory32Fixed (ReadOnly, - 0xFED00000, // Address Base - 0x00000400, // Address Length - ) - }) - } - } - Scope (_SB.PCI0) { Device (ISA) Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopher...@intel.com> --- hw/i386/acpi-build.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index bcb1f65c1d..73ec0b6d32 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -1405,7 +1405,9 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, aml_append(sb_scope, dev); aml_append(dsdt, sb_scope); - build_hpet_aml(dsdt); + if (misc->has_hpet) { + build_hpet_aml(dsdt); + } build_piix4_isa_bridge(dsdt); build_isa_devices_aml(dsdt); if (pm->pcihp_bridge_en || pm->pcihp_root_en) { @@ -1450,7 +1452,9 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, aml_append(dsdt, sb_scope); - build_hpet_aml(dsdt); + if (misc->has_hpet) { + build_hpet_aml(dsdt); + } build_q35_isa_bridge(dsdt); build_isa_devices_aml(dsdt); build_q35_pci0_int(dsdt); -- 2.17.1